<template>
    <div id="message" v-scroll-bottom="sessions">
        <ul v-if="currentSession">
            <li v-for = "entry in sessions[user.username+'#'+currentSession.username]">
                <p class="time">
                    <span>{{entry.date | time}}</span>
                </p>  
                <div class="main" :class="{self:entry.self}">
          <img class="avatar" :src="entry.self ? user.userFace : currentSession.userFace">
                    <p class="text">{{entry.content}}</p>
                </div>
            </li>
        </ul>
    </div>
  </template>
  
  <script>
  import {mapState} from 'vuex'
  
  export default {
    name: 'message',
    data () {
      return {
        user: JSON.parse(window.sessionStorage.getItem('user')),
      }
    },
    computed:mapState([
        'sessions',
        'currentSession'
    ]),
    filters:{
        time (date) {
        if (date) {
          date = new Date(date);
        }
            return `${date.getHours()}:${date.getMinutes()}`;
        }
    },
    directives: {/*这个是vue的自定义指令,官方文档有详细说明*/
      // 发送消息后滚动到底部,这里无法使用原作者的方法，也未找到合理的方法解决，暂用setTimeout的方法模拟
      'scroll-bottom' (el) {
        //console.log(el.scrollTop);
        setTimeout(function () {
          el.scrollTop += 9999;
        },1)
      }
    }
  }
  </script>
  
  <style lang="scss" scoped>
  #message {
      padding: 15px;
    max-height: 68%;
    overflow-y: scroll;
    ul {
        list-style-type: none;
        padding-left: 0px;
        li {
            margin-bottom: 15px;
        }
    }
    .time {
        text-align: center;
        margin: 7px 0;
        > span {
            display: inline-block;
            padding: 0 18px;
            font-size: 12px;
            color: #FFF;
            background-color: #dcdcdc;
            border-radius: 2px;
        }
    }
    .main {
        .avatar {
            float: left;
            margin: 0 10px 0 0;
            border-radius: 3px;
            width: 30px;
            height: 30px;
  
        }
        .text {
            display: inline-block;
            padding: 0 10px;
            max-width: 80%;
            background-color: #fafafa;
        border-radius: 4px;
        line-height: 30px;
        }
    }
    .self {
      text-align: right;
      .avatar {
        float: right;
        margin: 0 0 0 10px;
        border-radius: 3px;
        width: 30px;
        height: 30px;
      }
      .text {
        display: inline-block;
        padding: 0 10px;
        max-width: 80%;
        background-color: #b2e281;
        border-radius: 4px;
        line-height: 30px;
      }
    }
  }
  </style>
  